It is common practice of public and private services the use of lifting systems to maintain their facilities. These systems can be divided into two big groups: first are the fixed systems, which are those installed in the workplace and consist of a series of modular structures assembled (scaffolds), joined together to build the support on which the workers perform his duties. These systems are placed on the ground surface, and are fitted to the unevenness of the terrain through a series of supports with variable height and wedge-type devices.
The disadvantage of this first group of systems is that they require to be disassembled for being translated from a workplace to another, which implies loss of time both in assembling-disassembling process and moving.
On the other hand, there are the self-propelled systems, which are those mounted on a chassis that allows to move them to the workplace; these systems have the advantage of not requiring to be disassembled, so that the operation times are shorter in comparison with the modular systems.
The main drawback of the latter type of systems is that they require to be leveled to keep the stability and avoid rollovers, since the supporting area is smaller that of the fixed systems. Also, the use thereof in areas where the ground is not leveled is restricted by the chassis frame and the type of carrying vehicle (tracked built-in systems, attached to trucks, on not self-propelled chassis, etc.)
Among this type of self-propelled systems, the bucket trucks stand out, since being mounted on a vehicle chassis (such as a truck, a pick-up, or a tracked vehicle), they allow the worker to easily move them between different workplaces, being the systems mounted on vehicles complying with traffic regulations in public roadways those with greater autonomy and flexibility. However, to date its usefulness is limited because the axis of the crane arm must be leveled in relation to the horizontal plane, in order to provide stability to the system and prevent an excessive wear thereof. Usually this type of lifting systems are not designed to work in a steep slope, which severely limits its use in rough terrains or in urban areas located in the slopes of ground elevations.
Currently, as a rule an articulated bucket truck cannot operate at more than 5 degrees of tilt, since its stability is compromised when the center of gravity is displaced outside the chassis frame, thereby increasing the risk of rollovers and undesired swinging. Also, the bearings that allow the articulated arm to move suffer a greater wear when operating on slopes, wo that the useful life of such systems results severely reduced when compared to those that operate in leveled locations.